1. Field of the Invention
This invention relates to compositions and methods useful in inhibiting the growth of cariogenic bacteria and the formation of plaque on teeth in an oral environment.
2. Prior Art
The prevention of the formation of dental plaque is a highly desired result. Dental plaque results when cariogenic bacteria (e.g., Streptococcus Mutans), collect in colonies on the teeth and form a tenacious deposit thereon. The presence of the bacteria and the deposits is extremely detrimental to the health of the teeth. Thus, if the cariogenic bacteria and the plaque formation are not checked they may result in infected gingival tissue, the formation of dental caries and peridontal disease. In extreme cases they may ultimately result in the loss of the teeth.
To overcome these problems many attempts have been made to control each. For example, fluoride solutions or gels have been used. Treatment with these materials is typically performed in a dental office at periodic, but not frequent intervals. The primary objective of such treatments is to render the tooth enamel more resistant to the acid action caused by plaque. Such treatments do not, however, result in plaque control for an extended period since plaque reestablishes itself on the teeth shortly after ingestion of food.
Even when the frequency of application of such solutions and gels is increased only partial control has been shown. For example, studies wherein a fluoride-containing solution (1% fluoride concentration) was applied four to five times in the course of a year have demonstrated that this technique had only limited success due to the rapid reestablishment of plaque in the oral cavity. Moreover, the daily application of a fluoride gel by means of a customfitted polyvinyl mouthpiece for a period of 21 months also showed no substantial change in plaque formation among treated and untreated patients. See "Clinical Anticaries Effect of a Repeated Sodium Fluoride Application by Mouthpiece", Journal of the American Dental Association, V. 75, No. 3, September, 1967, pp. 638-644.
Other attempts at inhibiting the formation of plaque have also been made. Thus British Pat. No. 1,319,247 describes dental compositions which comprise a dental vehicle and a zinc, copper or zirconium complex of a fluorinated beta-diketone. These compounds are said to reduce the solubility of tooth enamel in the acids produced by bacteria in the mouth.